AB0794 A PROSPECTIVE STUDY ON RENAL INVOLVEMENT IN INDIAN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS
Authors: S. Ghosh, K. Telang, L. Sharma, G. Ekbote, D. Tanna, S. Dhuria, V. Singal, R. Gupta
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The ANCA-associated vasculitides (AAV) are systemic autoimmune diseases affecting small and medium-sized blood vessels. Upper airways, lungs, and kidneys are variably involved in the different types of AAV, and the consequences of a missed or delayed diagnosis of renal vasculitis are potentially life-threatening. AAV may be classified into clinical syndromes or based on their serology (Anti-PR3 or Anti-MPO). Patient survival and the risk of end-stage renal disease are closely associated with renal functional status. <h3>Objectives</h3> This study was undertaken to study the disease characteristics and outcomes in patients of AAV based on the presence or absence of renal involvement. <h3>Methods</h3> This was a longitudinal, observational study conducted at a tertiary care hospital in Northern India. Between February 2020 and December 2021, all consecutive adult patients diagnosed with AAV based on their autoantibody profiles (using indirect immunofluorescence and Line ImmunoAssay) and clinical features were included in this study after taking their informed consent. Demographic details, clinical features, laboratory parameters, disease activity, and mortality or morbidity outcomes of patients were analysed prospectively. All outcomes were compared between patients with and without renal involvement. <h3>Results</h3> A total of 112 patients were included in our study, with a median age of 51.5 years. 74 (66%) patients had renal involvement either in the form of Nephritic syndrome, Nephrotic syndrome, RPRF (Rapidly progressive renal failure), Nephritic nephrotic syndrome, or Asymptomatic Urinary Sediments. c-ANCA and PR3 positivity were seen in more than two-thirds of our population, without any significant correlation with organ involvement. Patients with renal disease had a significantly higher proportion with diffuse alveolar haemorrhage (32.4% vs 10.5%, p=0.05) and palpable purpura (19.6% vs 7.9%, p-0.025), but significantly lower occurrences of nasal pathology (14% vs 42%, p=0.001) and subglottic stenosis (1.4% vs 18.4%, p=0.001). Mean BVAS at enrolment was significantly higher in the renal group (20.9 vs 12.89). Remission was achieved in 50% and 47.4% of the patients with and without renal involvement respectively. Rates of relapse (19/74 vs 14/38), refractory disease, and mortality were not significantly different among the two subgroups. The commonest organ involvement in disease flare was pulmonary involvement. 21.6% of the patients developed CKD over a median follow-up period of 18 months. <h3>Conclusion</h3> Kidney involvement is one of the commonest manifestations of AAV. Patients with renal involvement may have higher mean BVAS scores and an increased risk of developing alveolar haemorrhage and purpuric skin rash; while nasal pathology and subglottic stenosis occurred more frequently in patients without renal disease. Rates of remission, refractory disease, and mortality were almost similar, regardless of renal involvement, while relapses were numerically more in the non-renal AAV patients. <h3>References</h3> [1]Stone JH, Merkel PA, Spiera R, Seo P, Langford CA, Hoffman GS, Kallenberg CG, St. Clair EW, Turkiewicz A, Tchao NK, Webber L. Rituximab versus cyclophosphamide for ANCA-associated vasculitis. New England Journal of Medicine. 2010 Jul 15;363(3):221-32. [2]Córdova-Sánchez BM, Mejía-Vilet JM, Morales-Buenrostro LE, Loyola-Rodríguez G, Uribe-Uribe NO, Correa-Rotter R. Clinical presentation and outcome prediction of clinical, serological, and histopathological classification schemes in ANCA-associated vasculitis with renal involvement. Clinical rheumatology. 2016 Jul;35(7):1805-16. [3]Kronbichler A, Shin JI, Lee KH, Nakagomi D, Quintana LF, Busch M, Craven A, Luqmani RA, Merkel PA, Mayer G, Jayne DR. Clinical associations of renal involvement in ANCA-associated vasculitis. Autoimmunity Reviews. 2020 Apr 1;19(4):102495. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.